China's police detention departments will be overhauled during a three-month campaign which began Wednesday to investigate the reasons behind a series of suspicious deaths of inmates at detention houses.

The deaths are suspected to have been results of bullying and torture at detention houses under police officers' control, triggering an outrage in the country.

The Ministry of Public Security said that the campaign would look into possible problematic areas around the issue, such as some police officers' low awareness of the law and human rights, and misuse of authority.

"We should be bold enough to expose our deficiencies, get to the bottom of the problems, and find and implement the solutions," the ministry said in a statement on its website on Tuesday.

The ministry also asked police officers at detention departments to strengthen professional ethics and propagate anti-corruption awareness.

The campaign came after the media exposed a series of suspected unnatural deaths of inmates at detention houses in the past two months.

The first case that caught the public's attention was the death of 24-year-old Li Qiaoming at the Jinning detention house in Yunnan province. Detention officers at first claimed Li died of an accident when playing hide-and-seek with inmates.

The excuse was so unpersuasive that it immediately led to protests on the Internet. After the Supreme People's Procuratorate stepped in, local authorities admitted that Li was beaten to death by prison bullies.

It then provoked media reports on similar suspicious cases of inmate deaths, including that of 19-year-old Xu Gengrong, who died on Mar 8, the seventh day of his detention in Shaanxi province. Xu was arrested on suspicion of stoning a schoolmate to death.

This week three more cases of custody death were reported. These include two minors who reportedly died over four days at a provincial juvenile reformatory in Hunan province, and 50-year-old Li Wenyan who reportedly died in the middle of "a nightmare", according to a detention department head in Jiujiang of Jiangxi province.

The campaign is the ministry's temporary measure to curb the improper doings of police officers at detention houses, Fan Chongyi, professor at China University of Political Science and Law, said in a phone interview yesterday.

"It aims to improve the police officers' professional awareness and regulate their behavior, but in order to strike at the root of the problems, the detention houses should be put into the hands of an independent department," he said,

"And the power of police officers at detention houses, which are supposed to be neutral ground for defendants till a verdict is reached, must be regulated by a checks and balanced mechanism," he said.